Telephone system.



R. TUCKER. TELEPHONE SYSTEM.

APPLIOATION FILED MAY 24, 1913.

1,100,856. Patented June 23, 1914.

2 SHEETS-SHEET 1.

Fig-1- wuemboz q/vflwwowo A-R. Tucker,

A. R. TUCKER.

TELEPHONE SYSTEM. APPLIOATION FILED MAY 24, 1913.

.Fgg 2- Patented June 23, 1914.

2 SHBETS'SHEET 2.

COLUMBIA PLANDGRAFH CD.,WASHINGTDN. n. c.

UNTTED STATES PATENT @FFTQE.

ALBERT R. TUCKER, OE LOTT, TEXAS.

TELEPHONE SYSTEM.

To all whom it may concern:

Be it known that I, ALBERT R. TUCKER, a citizen of the United States, residing at Lott, in the county of Falls and State of Texas, have invented certain new and useful Improvements in Telephone Systems; and I do declare the following to be a full,

clean and exact description of the invention,

such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in telephone systems and more particularly party line systei'ns. It is a well known dlsadvantage of the much used party line that as all the instrmnents are connected in par allel on main line, all parties have access to all the conversation carried on over the line, so that no private or personal matters may be discussed with safety.

The main object of the present invention is to eliminate this embarrassment to the user of the party line system, and I accomplish this and other objects which w1ll hereinafter appear by the combination, arrangement and construction of parts described and claimed in the following specification and illustrated in the accompanying drawings in which Figure 1 illustrates a party line having my invention incorporated in the two subscriber stations which are represented; Fig. 2 is a perspective view of a box to be placer adjacent to each subscribers telephone and to contain the apparatus used in my system; Fig. 3 is a vertical sectional view of the same; Fig. 4 is a rear view of thesame; and Fig. is an enlarged view of one of the keys.

In the drawings, Fig. 1 represents two subscriber stations on a party line embodying my invention and while I have illus trated but two of such stations and designated them A and B for convenience in this description, it will be understood that more are to be comprehended. The telephone party line L has at each of the subscribers stations a short section L which breaks the line at two places at such station; but such breaks are suitably closed atcertain times as will hereinafter appear.

At each subscribers station there are the usual parts, namely, the telephone T, the call bell C, three ground connections Gr, 100 and 101. In carrying out my invention, I also provide at each station batteries f, 2', h,

Specification of letters Patent.

Application filed May 24, 1913.

Patented June 23, rate.

Serial No. 769,747.

a suitable electrically operated signal (Z such for lnstance as a buzzer, a clrcuit closer 6 preferably an electromagnetic drop as shown, and five circuit closing keys a, a",

Z 5, and 0 which are of the usual (ringing or listening key) construction. These parts are preferably arranged on and in a box or other suitable casing B illustrated in Figs.

.the normally engaged contact springs 7 and 8, see Fig. l; and when these keys are raised, the main line is broken at two points and the telephone is connected to the line and ground. These keys may therefore be called line and ground keys. When the key a is actuated the contact spring 7 disengages the contact spring 8 and engages the contact spring 6 thereby connecting one end of the linethrough the conductors 5 and 51 to the telephone T. The other side of the Itelephone is connected by conductor 21 to a conductor 1 which connects with the springs Y 2 of the keys a, a. These springs 2 are normally out of contact with the co-acting con- .tact springs 3 of these keys. Springs 3 are connected by a conductor 4 to ground G. The telephone T 15 normally disconnected from the main line, but it will be seen that jWllGIl the keys 0, a are actuated the contact springs 2, 3 are engaged so that the branch 21 from the telephone is connected through them to ground, while the other branch 51 is connected through the springs 6, and 7 to the telephone line. The call bell C has one side connected to the main line L through conductors 9, short line L and contact springs 7 and 8, and the other side grounded through conductors l0 and 4:. By arranging the bell circuit in the manner described a subscriber at station B for in- 1 stance, actuating the keys a or a breaks his posed in each of the telephones T, and connected across the line to the conductors 51--21 as customary in telephones of this character, said magneto being operated by the handle 125 connected with its armature. When the keys (6 a have been actuated, one side of said magneto is connected with ground G, by conductor 21, contact springs 2 and 3, and conductor 4, the other side being connected to the main line L by conductor 51 and contact springs 6 and 7 Therefore if subscriber B desires to call subscriber A, he raises key a, then revolves the handle 125, which by reason of the aforementioned magneto which is connected therewith, a current will flow from one side of the magneto through conductor 21, contact springs 2 and 3 and conductor 4 to ground G, and from the other side of the magneto through conductor 51, contact springs 6 and 7, main line L, short line L, conductor 9, call bell C, conductor 10, to ground G of station A, hence making a complete circuit and ringing bell C of station A. On the other hand, if subscriber B, wishes to notify central, he merely actuates the keys a or a which grounds one side of the telephone and connecting the other side thereof with main line L in the manner hereinbefore described; removal of the receiver will then by reason of a ground connection and line signal located at central ofiice (and not herein shown), notify central that the subscriber is calling.

The keys 5, b are the battery keys and when in their actuated positions, (their levers thrown up), they connect the bat teries and i to each end of the main line. This is effected through conductors 11 and 34 which are connected to'the batteries and to contact springs 23 and 25 of each key 6, b. The contact springs 23 co-act with contact springs 24 which latter are connected by conductors 12 to the ends of the main line L; and the contact springs 26 which coact with the springs 25 are connected by conductors 13 to the short section L. It will therefore be seen that when the levers of the keys I), I) are thrown up to actuated positions, the two sides of each break in the main line will be connected to the one pole of battery f through conductors 11, contact springs 23 and 24 and conductors 12, the opposite pole of the battery being grounded through conductors 35, magnet a, conductor 33 and ground 100. lVhile the short line L is connected to one side of battery 2' through 'conductors 34;, contact springs 25 and 26 and conductors 13, the other pole of the battery 2' is grounded by reason of its connection with the ground 101.

O is the buzzer key which when actuated (its lever thrown up) closes one break in the buzzer circuit and also closes the line circuit through the coil of the electromagnet drop 6. In the key 0 the contact spring 27 is connected by conductor 14: to the line section L while its co-acting spring 30 is connected by a conductor 31 to the coil 32 of the drop 6, the other end of the coil being connected by a conductor 33 to the ground 100.

The armature 35 of this drop or circuit closer e carries a movable contact 18 adapted to engage a stationary contact 19 which is connected by a conductor 20 to contact spring 28 of the key 0. The coacting contact spring 27 is connected by conductor 36 to one terminal of the buzzer (Z. The adjacent terminal of said buzzer is connected by conductor 22 to one pole of the battery it, whose opposite pole is connected by conductor 17 to the movable contact 18. Therefore, when the movable contact has been actuated into contact with the station ary point 19, there will be a closed battery circuit through the buzzer d by reason of the connections hereinbefore set forth.

From the foregoing, it will be seen that each subscribers telephone is completely off the line with the exception of the call bell. Consequently central can at any time call the desired subscriber giving the proper signal. The circuit at each station will be from the main line L through conductor 9, bell C, conductor 10, a portion of conductor 1- to ground Gr, the two breaks in the main line at each station, that is at the ends of the short section L being closed by the contact spring 7-8 of keys a, a. After the ringing of call bell G, subscriber B to ascertain the direction of the call, first raises the key a if he receives no response, he lowers the latter and raises a which, places him in communication with the party calling. Now if we assume that central is on the left of station A and station E is called, the subscriber at station B first pushes up the lever to key a which connects the telephone T to the left end of the line and breaks the line on the right end, and further 110 grounds one terminal of the telephone as explained above. Thus, it will be seen that all instruments to the right of station 15 are cut ofi and should an intermediate station such as A try to connect with the line, 115 the key a of station A would have to be operated and that would result in breaking the line and disconnecting B. After the subscriber at B has operated key a to accomplish the foregoing, he lifts the lever to 120 the next key Z) (of course it will here be noted that if the call emanates from the right a and I) would be the proper keys to operate) which connects one pole of bat tery f to the main line L and grounds its 125 other pole and also connects the short line L to the ungrounded pole of battery 6 in a manner hereinbefore set forth. My object in connecting the batteries in this manner is to cause the energization of the 130 magnetic circuit closer or drop e of an intermediate station such as A so that the second break in the buzzer circuit at station A would be closed by the contacts 18-19, the first break in such circuit being closed by the contact springs 272S when subscriber A operates the key 0. It will thus be observed, still assuming that subscriber B is talking over the line to a party or central to the left of station A that should A break in on the line by operating the key a or a, B would be cut off the line; but should A desire to use the telephone not knowing that the line is in use, actuate the key 0 the buzzer cl at station A would immediately sound an alarm indicating to him that the line is busy and this actuation of the buzzer would not disturb the users of.

the line. If no one is speaking over the line the buzzer (Z will not sound when the key 0 is pressed because only one break in the buzzer circuit (that of the springs 272-8) will be closed the other break between parts l819 not being closed until the electromagnetic circuit closer e is actuated by current from one of the batteries f or 2' connected to the line by one of the keys b-b.

From the foregoing it will be seen that by providing at each subscribers station the additional parts mentioned above and making the proper electrical connection which may be as shown in Fig. 1 or in any other suitable manner, any subscriber breaking in on the line can ascertain whether or not the line is busy, and should he intentionally break into the line to listen to the conversation the line will be broken.

Having thus described my invention, what I claim is:

1. In a telephone system the combination with a plurality of subscribers stations and a party line, connecting them, of means manually operated and located at each station to break the main line, and connect one side of the telephone to ground and the other side thereof to the main line, batteries at each station, means at the latter for manually connecting two of the batteries to the two ends of the party line respectively when a subscriber is talking, a signal at each station actuated by the remaining battery to indicate the condition of the line, and manually controlled means actuated by a sub-- scriber who is not talking for closing the circuit of the last mentioned battery through said signal.

2. In a telephone system the combination with a plurality of subscribers stations and a party line connecting them, of means manually operated and located at each station to break the main line and connect one side of the telephone to ground and the other side thereof to the main line, a local signal circuit at each station including batteries, a signal and two normally open circuit closers, means for manually operating one of said circuit closers, and means whereby the other will be automatically operated through the manually operated one when this party line is busy.

3. In a telephone system, the combination with a plurality of subscriber stations and a party line connecting them, and including a short section at each of said stations, of batteries at each station, means for connecting two of said batteries onto the two ends of the party line respectively when a subscriber is talking, a signal and signal controlling switches at each subscribers station, and means whereby the circuit of the remaining battery is closed through the signal when the subscriber operates his switches while the party line is busy.

4. In a telephone system, the combination with a plurality of subscriber stations and a party line connecting them, and including a short section at each of said stations, of batteries at each station .two of which are provided with two different ground connections, two battery switches at each station for connecting the grounded batteries to the two ends of the main line respectively, two line and ground switches at each station to break the main line and connect the telephone to ground and to the line, a signal at each station, a magnetic circuit closer at each station included in the circuit of the signal and the remaining non-grounded battery and a signal key also included in the circuit of the signal and non-grounded battery arranged to close the circuit to the coil of the magnetic circuit closer and to also close one of the two breaks in the signal circuit.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

ALBERT R. TUCKER.

Witnesses:

A. G. HENKE, HENRY Lo'r'r.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, I). C. 

